Package mondrian.udf

Class NullValueUdf

java.lang.Object

mondrian.udf.NullValueUdf

All Implemented Interfaces:

UserDefinedFunction

public class NullValueUdf
extends Object
implements UserDefinedFunction

Definition of the user-defined function "NullValue" which always returns Java "null".

Author:

remberson,jhyde

Nested Class Summary

Nested classes/interfaces inherited from interface mondrian.spi.UserDefinedFunction

UserDefinedFunction.Argument

Constructor Summary

Constructors

Constructor	Description
NullValueUdf()

Method Summary

Modifier and Type	Method	Description
Object	execute(Evaluator evaluator, UserDefinedFunction.Argument[] arguments)	Applies this function to a set of arguments, and returns a result.
String	getDescription()	Returns a description of the user-defined function.
String	getName()	Returns the name with which the user-defined function will be used from within MDX expressions.
Type[]	getParameterTypes()	Returns an array of the types of the parameters of this function.
String[]	getReservedWords()	Returns a list of reserved words used by this function.
Type	getReturnType(Type[] parameterTypes)	Returns the return-type of this function.
Syntax	getSyntax()	Returns the syntactic type of the user-defined function.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NullValueUdf

public NullValueUdf()

Method Detail

getName

public String getName()

Description copied from interface: UserDefinedFunction

Returns the name with which the user-defined function will be used from within MDX expressions.

Specified by:

getName in interface UserDefinedFunction

getDescription

public String getDescription()

Description copied from interface: UserDefinedFunction

Returns a description of the user-defined function.

Specified by:

getDescription in interface UserDefinedFunction

getSyntax

public Syntax getSyntax()

Description copied from interface: UserDefinedFunction

Returns the syntactic type of the user-defined function. Usually Syntax.Function.

Specified by:

getSyntax in interface UserDefinedFunction

getReturnType

public Type getReturnType(Type[] parameterTypes)

Description copied from interface: UserDefinedFunction

Returns the return-type of this function.

Specified by:

getReturnType in interface UserDefinedFunction

Parameters:

parameterTypes - Parameter types

Returns:

Return type

getParameterTypes

public Type[] getParameterTypes()

Description copied from interface: UserDefinedFunction

Returns an array of the types of the parameters of this function.

Specified by:

getParameterTypes in interface UserDefinedFunction

execute

public Object execute(Evaluator evaluator,
                      UserDefinedFunction.Argument[] arguments)

Description copied from interface: UserDefinedFunction

Applies this function to a set of arguments, and returns a result.

Specified by:

execute in interface UserDefinedFunction

Parameters:

evaluator - Evaluator containts the runtime context, in particular the current member of each dimension.

arguments - Expressions which yield the arguments of this function. Most user-defined functions will evaluate all arguments before using them. Functions such as IIf do not evaluate all arguments; this technique is called lazy evaluation.

Returns:

The result value.

getReservedWords

public String[] getReservedWords()

Description copied from interface: UserDefinedFunction

Returns a list of reserved words used by this function. May return an empty array or null if this function does not require any reserved words.

Specified by:

getReservedWords in interface UserDefinedFunction